Lubricating apparatus



OV- 1952 E. w. DAVIS 6,523

LUBRICATING APPARATUS Original Filed Aug. 18, 1943 5 Sheets-Sheet l Nov.4, 1952 E. w. DAVIS 2,616,523

LUBRICATING APPARATUS Original Filed Aug. 18, 1943 3 Sheets-Sheet 2 E.w. DAVIS 2,616,523

3 Sheets-Sheet 3 Nov. 4, 1952 LUBRICATING APPARATUS Original Filed Aug.18, 1945 Patented Nov. 4, 1952 LUBR-ICATING APPARATUS Ernest W. Davis,River Forest, Ill.

Substituted for application Serial No. 499,157, August 18, 1943. Thisapplication January 11, 1946, Serial No. 640,526

18 Claims. 1

My invention relates to lubricating apparatus, and more particularly toa power driven lubricant pump provided with mechanism for automaticallystarting the pump in operation at regularly recurring time intervals,whereupon the pump builds up a predetermined lubricant pressure, thenautomatically stops pumping, and releases the pressure. A pump of thisclass is useful for supplying lubricant to a plurality of measuringvalves designed for proportioning the flow of lubricant to a pluralityof bearings requiring lubrication.

One object of this invention is to provide a pump of the classdescribed, which is durable and dependable in operation, which is simplein construction, and which can be manufactured at a comparatively lowcost.

Another object is to provide means for immediately releasing thepressure at the outlet of the pump as soon as the required predeterminedpressure has been reached. These and other objects will appear as thedescription proceeds.

The generic principle of this invention is adaptable for embodiment ineither an air driven pump or an electrically driven pump, both of whichare illustrated in the accompanying drawings, in which Fig. l is anelevation of the air driven pump, shown partly in central longitudinalsection;

Fig. 2 is an elevation of the electrically driven pump, shown partly incentral longitudinal section;

Fig. 3 is an end elevation of the control box for controlling theelectric motor illustrated in Fig. 2;

Fig. 4 is a section through the control box, the section being made onthe line 4-4 of Fig. 3; and

Fig. 5 is a diagrammatic view of the controlling mechanism and theelectric wiring used therein.

This application is a substitute application for my prior abandonedapplication, Serial No. 499,157, filed August 18, 1943.

Referring to Fig. 1, the air driven pump utilizes a lubricant container6 for holding lubricant to be pumped (not shown), and is provided with apump cylinder '1, in which the piston 8 reciprocates. The piston rod 9is driven with reciprocating motion by the air engine H), which may beconstructed in accordance with any one of many designs, well known tothose skilled in the art. The foot valve I! prevents reverse flow oflubricant from the cylinder 1 to the container 6, and the check valve [2prevents reverse flow of lubricant through the piston 8, so thatreciproeating movement of thepiston 8 will cause lubri- 2 cant to bewithdrawn from the lubricant container 6 and discharged into thedischarge outlet l3, as will be readily understood.

The controlling mechanism for controlling the operation of the airengine It will now be described. The air fitting I4 is adaptable forconnection with an air coupling on an air hose connected with a sourceof air under pressure. Throughout the period of use of the apparatus,compressed air flows through the air fitting it into the lowermost partof the air cylinder 15, where it exerts a continuous upward pressureagainst the piston 16, which pressure continuously tends to urge thepiston IE to move in an upward direction, thereby tending to hold thevalve ll against its seat l8, which is of smaller area than the pistonHi. In this deenergizing position of the valve ll, the compressed air isconfined within the air cylinder l5, and therefore cannot operate theair engine [0, which remains stationary until the valve I1 is opened bymeans which will now be described.

The force of gravity continuously tends to urge the weight 19 in adownward direction, but its downward movement is retarded by restrictionto at flow of oil from the oil cylinder 20 through the adjustable needlevalve 2|, as caused by the resulting downward movement of the piston 22.The oil contained in the oil cylinder 20 may be composed of a mixture ofcastor oil and alcohol, which mixture has a nearly constant viscositythroughout ordinary normal changes in temperature, so that the weight 19will always descend at a uniform rate of motion. Manual adjustment ofthe needle valve 2| may be used for adjusting the downward movement ofthe weight [9, so as to provide the rate of movement desired.

As the weight l9 continues to move in a downward direction, it willeventually engage the pin 23, so as to compress the spring 24. When thespring 24 is compressed sufiiciently, it pops the valve I! to its openposition and closes the valve 26 against the valve seat 2?. When thevalve H opens, the resulting momentary decrease of air pressure againstthe piston l6 tends to give the valve a desirable pop action, and amomentv later the air pressure above the valve 26 holds the valve 28down against its seat 21 with a force in excess of the upward pressureagainst the piston [5, because the area of the valve 26 is greater thanthat of the piston I5.

Compressed air then passes through the port 28 and into the air cylinder29, thereby exerting an upward thrust on the plunger 30, so as to raisethe weight I9 until the piston 22 engages 3 the boss 3!. During thisupward movement of the piston 22, oil within the oil cylinder passesthrough the openings 32, and around the check valve 33.

Compressed air also passes from the air cylinder 29 into the air tubes34 and and into the air engine l5, which then begins reciprocating thepiston 8 so as to pump lubricant under pressure into the dischargeoutlet I3. Compressed air also passes through the air tube 35, and intothe air cylinder 37, where it urges the piston 38 up-- wardly to closethe pressure release valve 39, whereby pressure may be built up in thedischarge outlet I3. It is understood, of course, that the dischargeopening it! is connected with a lubricant line for conducting lubricantto a plurality of suitable metering devices for proportioning thedischarge of lubricant into a plurality of bearings requiringlubrication.

After the metering devices have discharged their measured amounts oflubricant, they automatically obstruct any further flow of lubricantinto the bearings, so that the pressure then builds up in the dischargeoutlet until the lubricant pressure transmitted through the tube H andinto the lubricant cylinder i2, pushes the plunger 43 upwardly, therebyforcing the valve pin 44 against the valve 26, so as to open the valveagainst the action of the air pressure that tends to hold the valve 26closed. There is suificient compressibility in the lubricant filling thelubricant line, and in the air in the air engine, to move the valve 26upwardly so as to seat the valve I! in a fraction of a second, whereuponthe air pressure in the air cylinder I5 then retains the valve I? in itsclosed position by xerting pressure against the piston I 6 in the mannerhereinbefore described.

When the valve I1 is closed, the valve 26 is opened, so that the airexhaust port then connects the air cylinders 29 and 3'! with theatmosphere, thereby dissipating their internal pressures. The internalpressure in the air engine I0 is dissipated at the same tim and stopsoperating. The lubricant pressure acting on the valve 39, which is nolonger held closed by air pressure, causes the valve 33 to open,whereupon lubricant flows from the discharge outlet I 3, past thepressure release valve 39, out through the lubricant vent 46, and backinto the container 5. The absence of air pressure in the air cylinder 29then permits the weight I9 to move downwardly, so that after apredetermined time interval, depending in duration upon the adjustmentof the needle valve 2 I, the cycle of operation hereinbefore describedwill be repeated.

The functions of the various elements of this pump have been explained,and the complete operation will now be described.

The weight I9 falls slowly by the action of gravity, thereby displacingoil in the oil cylinder 28 at a rate determined by the setting of theneedle valve 2I, so as to retard the movement of the weight I9 toprovide a, time cycle of the desired duration. When the weight I9engages the pin 23, the spring 24 is compressed and then pops the valveI! to its open position, in the manner hereinbefore described, therebyclosing the valve 26 and applying air pressure to the air engine II],and the air cylinders 29 and 31. This starts th air engine Ill inoperation, it raises the weight I9 to its uppermost position, and itcloses the pressure release valve 39 in the manner hereinbeforedescribed. Lubricant pressure built up in the lubricant cylinder 42 thenforces the plunger 4 43 upwardly to close the valve I! and open thevalve 26, thereby stopping the air engine It and allowing the pressurerelease valve 39 to open. The weight I9 then begins to fall inrepetition of the cycle of operation just described.

In the electrically driven pump, Fig. 2, the lubricant container 41contains lubricant (not shown) for supplying the lubricant pump 48. Thepump 48 is provided with a piston rod 49, which is reciprocated by theconnecting rod 55 actuated by the worm gear 5I. The worm gear M isdriven by the worm 52, which is rotated by the electric motor 53. Thelubricant pump 28 discharges lubricant under pressure into the lubricanttube 54 and the conduit 55, which connects with the lubricant line 56containing a number of measuring devices 57 for proportioning the flowof lubricant into the bearings 58.

The control box 55 (shown in greater detail in Fig. 4) contains amercury switch 58, which is supported by a tilting bracket 55 pivotedatthe pivot pin 62. The tilting bracket BI is moved in a clockwisedirection by engagement of the rotatable cam 63 with the roller 3d, andis moved in a counterclockwise direction by the action of gravity. Aself-starting synchronous clock-type motor 65 is provided with a slowspeed shaft to which is secured a driving arm 5?, which engages the lug68 to cause rotation of the cam t3, which is rotatable on the shaft 55.

When rotation of the cam 53 in a counterclockwise direction closes themercury switch 65, cur rent is supplied to the electromagnet 53, asindicated in the wiring diagram (Fig. 5) and this results in thearmature Ill being held against the magnet 69 so as to retain the switch53 in closed position independent of the action of the cam 63. Referringagain to Fig. 4, it will be observed that the cam 63 is cut away at H,so that the center of gravity of the cam 63 will lie at the left of theshaft 56. Owing to this eccentric center of gravity of the cam 63, whichis freely rotatable on the shaft 65, the retention of the armature Til)permits the cam 63 to rotate by the action of gravity to the advancedposition illustrated by the dotted lines. With the cam in this position,the release of the armature ill by means which will be describedhereinafter, will permit sufiicient movement of the tilting bracket 6|in a counterclockwise direction so as to open the switch till.

Referring again to Fig. 5, it will be observed that the synchronousmotor 65 is in continuous connection with the power lines 72 and '53, sothat the motor 65 will run continuously. This will produce intermittentclosing of the mercury switch 60, and each time the switch is closed itsupplies current to the magnet 69, the solenoid l4, and the electricmotor 53. Rotation of the motor 53 results in building up a pressure inthe lubricant tube 54 (Fig. 2) as explained hereinbefore, and thispressure is transmitted by the connecting tube I5, to the lubricantcylinder !5 (Fig. 4). When the solenoid M is energized, it moves thearmature I1 upwardly, and this causes upward oscillating movement of thelever 73, so that the plunger 19 is moved forcefully towards the right,thereby holding the ball valve 8t closed against the lubricant pressurein the lubricant cylinder I6.

When the lubricant pressure in the lubricant cylinder 16 reaches apredetermined value, it causes upward movement of the plunger 8! againstthe action of the spring 32, so that the thrust pin 83 engages thetilting bracket BI, and forcibly separates the armature i!) from themagnet 69., thereby openingthe switch ill and permitting the motor 53.to stop rotating, and there.- by deencrgizing the magnet 69: and thesolenoid 14. This. permits the armature l1 and lever 18 to fall to thepositions shown in Fig. 4, so that the lubricant under pressure in thelubricant cylinder 16 can then open the valve 80 and pass through thehollow screw 84, and into the gear box 85, where the successivedischarges may accumulate and furnish lubrication for the working partscontained therein. In the course of time, excess lubricant may escapethrough the vent opening 88 (Fig. 2) and drop back into the lubricantcontainer 41.

The functions of the various elements of this pump have been explained,and the complete operation will now be described.

The synchronous motor 65 (Fig. 4) runs continuously and rotates the cam83 in a. counter clockwise direction. Engagement of the cam with theroller 64 causes intermittent closing of the mercury switch Bil. Eachtime the tilting bracket 6! is moved so as to close the switch 60, themagnet 69, solenoid l4, and electric motor 53 are energized. This causesthe magnet to retain the armature 10 so that the switch 60 is retainedin its closed position. Tilting of the bracket 6| in a clockwisedirection allows the cam 53 to ad-- Vance slightly so as to permitreopening of the switch 60, and it results in closing of switch 5 toenergize. the solenoid l4 and thereby close the ball valve 80 so thatlubricant pressure can be built up in the lubricant line 55 (Fig. 2)When a predetermined pressure has been attained, the lubricant pressurein the lubricant cylinder 16 (Fig. 4) causes the thrust pin 83 to openthe switch 60. The electric motor 53 then stops, the ball valve 80 isopened by the lubricant pressure, and the magnet 69 no longer attractsthe armature l0. Continued rotation of the cam 63 then causes the abovecycle of operation to be repeated at regularly recurring time intervals.

It will be observed that in both the air operated pump and theelectrically driven pump, the pressure is released as soon as it reachesa predetermined value. The two pumps, although different in appearance,and fundamentally similar in that they both employ the same genericprinciple of operation. In each construction the lubricant pump isdriven by operating mechanism actuated by a source of power controlledby a movable member, movable to starting and stopping positions. Theyeach provide means, operable while the apparatus is in use, continuouslytending to urge said movable member towards said stopping position. Theyeach provide means for moving the movable member against the action ofsaid urging means to said starting position. They each provide means forretaining the movable member in that position, and they each providemeans, responsive to the lubricant pressure, for rendering the retainingmeans ineffectual, so that the urging means may then move the movablemember to said stopping position and thereby stop the pump.

Without further elaboration, the foregoing will so fully explain myinvention that others may, by applying knowledge current at the time ofapplication, readily adapt the same for use under various conditions ofservice.

I claim:

1. In lubricating apparatus, a lubricant pump having a discharge outlet,power driven operating mechanism having a drivin connection with saidpump for operating said lubricant pump, a

source of power,. power controlling means connected with said source andwith said. operating mechanism for intermittently connecting saidoperating mechanism with said source of power, said power control-lingmeans including a movable member movable to an energizing position inwhich said operating mechanism is connected with said source of power,and to a deenergizing position. in which said operating mechanism isdisconnected from said source of power, means continuously tending tourge said movable member toward said deenergizing position while theapparatus is in use, movable means mechanically engageable with saidmovable member for moving said movable member to said energizingposition, other means for retaining said movable member in saidenergizing position, and means movable. in response to the lubricantpressure in said discharge outlet and mechanically engageable with saidmovable member for rendering said retaining means ineffectual, wherebysaid urging means may then. move said movable member to. saiddeenergizing position.

2. In lubricating apparatus, a lubricant pump having a discharge outlet,power driven operating mechanism having a driving connection with saidpump for operating said lubricant pump, a source of power, powercontrolling means connected with said source and with said operatingmechanism for intermittently connecting said operating mechanism withthe source of power, said power controlling means including a movablemember movable to an energizing position in which said operatingmechanism is connected with said source of power, and to a deenergizingposition in which said operating mechanism is disconnected from saidsource of power, means operable throughout the period of use of theapparatus continuously tending to urge said movable member toward saiddeenergizing position, time responsive movable means mechanicallyimpingeable upon. said movable member for intermittently moving saidmovable member to said energizing position, other means for retaining.said movable member in said energizing position, and means movable inresponse to the lubricant pressure in said discharge outlet andmechanically impingcable upon said movable member for rendering saidretaining means inefiectual, whereby said urging means may then movesaid movable member to said deenergizing position.

3. In lubricating apparatus, a lubricant pump having a discharge outlet,operating mechanism for operating said lubricant pump, said operatingmechanism being actuated by a supply of fluid under pressure, valvemeans including a valve member for controlling the flow of said fluid tosaid operating mechanism, said valve member being movable to open andclosed positions, means continuously tending to urge said valve membertoward said closed position, movable means mechanically engageable withsaid valve member for intermittently moving said valve member to saidopen position, other means for retaining said valve member in said openposition, and means movable in. response to the lubricant pressure insaid discharge outlet and mechanically engageable with said valve memberfor rendering said retaining means ineffectual, whereby said urgingmeans may then move said valve to said closed position,

4.. In lubricating apparatus, a lubricant pump having a dischargeoutlet, operating mechanism. for operating said lubricant pump, saidoperating mechanism being actuated by a supply of fluid under pressure,a valve for controlling the flow of said fluid to said operatingmechanism, said valve being movable to open and closed positions, fluidpressure actuated means continuously tending to urge said valve towardsaid closed position, means for intermittently moving said valve to saidopen position, other means for retaining said valve in said openposition, and means responsive to the lubricant pressure in saiddischarge outlet for rendering said retaining means ineffectual, wherebysaid urging means may then move said valve to said closed position.

5. In lubricating apparatus, a lubricant pump having a discharge outlet,operating mechanism for operating said lubricant pump, said operatingmechanism being actuated by a supply of fluid under pressure, a valvefor controlling the flow of said fluid to said operating mechanism, saidvalve being movable to open and closed positions, means continuouslytending to urge said valve toward said closed position, resilient meansfor opening said valve against the action of said urging means, timecontrolled means for en ergizing said resilient means, means other thansaid resilient means for retaining said valve in said open position, andmeans responsive to the lubricant pressure in said discharge outlet forrendering said retaining means ineiTectual, whereby said urging meansmay then move said valve to said closed position.

6. In lubricating apparatus, a lubricant pump having a discharge outlet,operating mechanism for operating said lubricant pump, said operatingmechanism being actuated by a supply of fluid under pressure, a valvefor controlling the flow of said fluid to said operating mechanism, saidvalve being movable to open and closed positions, means continuouslytending to urge said valve toward said closed position, means forintermittently moving said valve to said open position, means actuatedby said fluid pressure for retaining said valve in said open position,and means responsive to the lubricant pressure in said discharge outletfor rendering said retaining means ineffectual, whereby said urgingmeans may then move said valve to said closed position.

7. In lubricating apparatus, a lubricant pump having a discharge outlet,operating mechanism for operating said lubricant pump, said operatingmechanism being actuated by a supply of fluid under pressure, a valvefor controlling the flow of said fluid to said operating mechanism, saidvalve being movable to open and closed positions, means continuouslytending to urge said valve toward said closed position, gravity actuatedmeans for intermittently moving said valve to said open position, othermeans for retaining said valve in said open position, and meansresponsive to the lubricant pressure in said discharge outlet forrendering said retaining means ineffectual, whereby said urging meansmay then move said valve to said closed position.

8. In lubricating apparatus, a lubricating pump having a dischargeoutlet, operating mechanism for operating said lubricant pump, saidoperating mechanism being actuated by a supply of fluid under pressure,a valve for controlling the flow of said fluid to said operatingmechanism, said valve being movable to open and closed positions, meanscontinuously tending to urge said valve toward said closed position, aWeight, means actuated by the pressure of said fluid for intermittentlyraising said weight, means actuated by the falling of said weight formoving said valve to said open position against the action of saidurging means, means independent of the position of said weight forretaining said valve in said open position, and means responsive to thelubricant pressure in said discharge outlet for rendering said retainingmeans ineflectual, whereby said urging means may then move said valve tosaid closed position.

9. In lubricating apparatus, a lubricant pump having a discharge outlet,operating mechanism for operating said lubricant pump, said operatingmechanism being actuated by a supply of fluid under pressure, a valvefor controlling the flow of said fluid to said operating mechanism, saidvalve being movable to open and closed positions, means continuouslytending to urge said valve toward said closed position, gravity actuatedmeans for intermittently moving said valve to said open position,retarding means for retarding the motion produced by said gravityactuated means, means other than said gravity actuated means forretaining said valve in said open position, and means responsive to thelubricant pressure in said discharge outlet for rendering said retainingmeans ineffectual, whereby said urging means may then move said valve tosaid closed position.

10. In lubricating apparatus, a lubricant pump having a dischargeoutlet, operating mechanism for operating said lubricant pump, saidoperating mechanism being actuated by a supply of fluid under pressure,a Valve for controlling the flow of said fluid to said operatingmechanism, said valve being movable to open and closed positions, meanscontinuously tending to urge said valve toward said closed position, aweight, means actuated by the pressure or" said fluid for intermittentlyraising said weight, means actuated by the falling of said weight formoving said valve to said open position against the action of saidurging means, means independent of the position of said weight forretaining said valve in said open position, means responsive to thelubricant pressure in said discharge outlet for rendering said retainingmeans ineffectual, whereby said urging means may then move said valve tosaid closed position, and means responsive to the lubricant pressure insaid discharge outlet for releasing the pressure of said fluid in saidweight raising means.

11. In lubricating apparatus, a lubricant pump having a dischargeoutlet, operating mechanism for operating said lubricant pump, saidoperating mechanism being actuated by a supply of fluid under pressure,a valve for controlling the flow of said fluid to said operatingmechanism, said valve being movable to open and closed positions, meanscontinuously tending to urge said valve toward said closed position, atiming device ener gized by said fluid pressure, means responsive tosaid timing device for intermittently moving said valve to said openposition, other means for retaining said valve in said open position,and means responsive to the lubricant pressure in said discharge outletfor rendering said retaining means inefiectual, whereby said urgingmeans may then move said valve to said closed position.

12. In lubricating apparatus, a lubricant pump having a dischargeoutlet, electrically powered op erating mechanism for operating saidlubricant pump, a switch for controlling the supply of electricity tosaid operating mechanism, said switch being movable to open and closedpositions, means continuously tending to urge said switch toward saidopen position, movable means mechanically engageable with said switchfor intermittently moving said switch to said closed position, othermeans for retaining said switch in said closed position, and meansmovable in response to the lubricant pressure in said discharge outletand mechanically engageable with said switch for rendering saidretaining means ineffectual, whereby said urging means may then movesaid switch to said open position.

13. In lubricating apparatus, a lubricant pump having a dischargeoutlet, electrically powered operating mechanism for operating saidlubricant pump, a switch for controlling the supply of electricity tosaid operating mechanism, said switch being movable to open and closedpositions, gravity actuated means continuously tending to urge saidswitch toward said open position, movable means impingeable upon saidswitch for intermittently moving said switch to said. closed position,other means for retaining said switch in said closed position, and meansresponsive to the lubricant pressure in said discharge outlet andimpingeable upon said switch for rendering said retaining meansineffectual, whereby the action of gravity may then move said switch tosaid open position.

14. In lubricating apparatus, a lubricant pump having a dischargeoutlet, electrically powered operating mechanism for operating saidlubricant pump, a switch for controlling the supply of electricity tosaid operating mechanism, said switch being movable to open and closedpositions, means continuously tending to urge said switch toward saidopen position, a rotating cam for actuating said switch, means forrotating said cam at a uniform rate of speed, means for periodicallyaccelerating the speed of said cam, means responsive to the closing ofsaid switch for retaining said switch in said closed position, and meansresponsive to the lubricant pressure in said discharge outlet forrendering said retaining means ineffectual, whereby said urging meansmay then move said switch to said open position.

15. In lubricating apparatus, a lubricant pump having a dischargeoutlet, electrically powered operating mechanism for operating saidlubricant pump, a switch for controlling the supply of electricity tosaid operating mechanism, said switch being movable to open and closedpositions, means continuously tending to urge said switch toward saidopen position, a cam for actuating said switch, means for driving saidcam, means for periodically advancing said cam relative to said drivingmeans, means responsive to the closing of said switch for retaining saidswitch in said closed position, and means responsive to the lubricantpressure in said discharge outlet for rendering said retaining meansineffectual, whereby said urging means may then move said switch to saidopen position.

16. In lubricating apparatus, a lubricant pump having a dischargeoutlet, electrically powered operating mechanism for operating saidlubricant pump, a switch for controlling the supply of electricity tosaid operating mechanism, said switch being movable to open and closedpositions, means continuously tending to urge said switch toward saidopen position, a rotatable shaft, means for rotating said shaft, arotatable cam driven by said shaft and rotatable relative thereto, meansresponsive to the closing of said switch for advancing said cam relativeto said rotatable shaft, means responsive to the rotation of said camfor moving said switch to said closed position, means responsive to theclosing of said switch for retaining said switch in said closedposition, and means responsive to the lubricant pressure in saiddischarge outlet for rendering said retaining means inefiectual, wherebysaid urging means may then move said switch to said open position.

17. In lubricating apparatus, a lubricant pump having a dischargeoutlet, electrically powered operating mechanism for operating saidlubricant pump, an electric switch for controlling the electricitysupplied to said operating mechanism, said switch being movable to openand closed positions, gravity actuated means for opening said switch,movable mechanical means engageable with said switch for closing saidswitch against the action of said gravity actuated means,electromagnetic means for retaining said switch in said closed position,and means movable in response to the lubricant pressure in saiddischarge outlet and engageable with said switch for rendering saidretaining means ineffectual.

18. In lubricating apparatus, a lubricant pump having a dischargeoutlet, electrically powered operating mechanism for operating saidlubricant pump, a switch for controlling the supply of electricity tosaid operating mechanism, said switch being movable to open and closedpositions, means continuously tending to urge said switch toward saidopen position, movable means impingeable upon said switch forintermittently moving said switch to said closed position, other meansfor retaining said switch in said closed position, means impingeableupon said switch in response to the lubricant pressure in said dischargeoutlet for rendering said retaining means ineffectual, whereby saidurging means may then move said switch to said open position, a pressurerelease valve for releasing the lubricant pressure in said dischargeoutlet, and electrically actuated means for controlling said pressurerelease valve, said valve controlling means being controlled by saidswitch.

ERNEST W. DAVIS.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,737,124 Phelps Nov. 26, 19291,799,026 Serpas Mar. 31, 1931 1,900,754 Blanchard Mar. 7, 19332,206,335 Rotter July 2, 1940 2,328,812 Klein Sept. 7, 1943 2,339,532Venable Jan. 18, 1944

